An adequate ductile fracture locus has to be developed to reasonably model crack initiation and propagation in high velocity impact. Most of the fracture loci in the literature were proposed on the basis of tensile tests while in high velocity impact cracks usually occur in the region where shear and compression are dominant. In this paper, perforation response of a thin beam struck by a rigid, blunt projectile moving at a high velocity is simulated using, respectively, uniform fracture strain, Johnson-Cook's, and Bao-Wierzbicki's fracture locus for 2024-T351 aluminum alloy. The former two predict that materials in the impacted area of the beam beneath the rigid mass fail layer by layer, which is not consistent with experimental observations. By contrary, Bao-Wierzbicki's fracture locus, which was developed from up-setting, shear and tensile tests, and covers the whole range of the stress triaxiality, is capable of capturing all of the features occurring in the whole failure process. Numerical results reveal that the beam would fail by shear plugging at a high impact velocity and by tensile tearing at a velocity near the ballistic limit.
